Bjugn is a former municipality in Trøndelag county, Norway. The municipality existed from 1853 until its dissolution in 2020 when it was merged into Ørland Municipality. It was part of the Fosen region. The village of Botngård was the administrative centre of Bjugn municipality. Other villages in Bjugn included Høybakken, Jøssund, Lysøysundet, Nes, Oksvoll, and Vallersund. Bjugn was on the Robek-list in 2015.
At the time of its dissolution in 2020, the municipality was the 245th largest by area out of the 422 municipalities in Norway. Bjugn was the 207th most populous municipality in Norway with a population of 4,864. The municipality's population density was and its population had increased by 5.6% over the last decade.
The municipality of Bjugn was established in 1853 when it was separated from the large municipality of Ørland. Initially, Bjugn had 2,903 residents. On 26 March 1870, a royal resolution moved an unpopulated part of Aafjord to Bjugn. On 1 January 1899, the municipality of Bjugn was divided into three municipalities. The western district (population: 1,285) became the municipality of Nes. The southern district (population: 2,166) became the municipality of Skjørn. The rest of the municipality (population: 1,256) remained the (much smaller) municipality of Bjugn.
During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1964, the neighboring municipalities of Nes (population: 1,107), Jøssund (population: 1,917), Bjugn (population: 1,240), and the northern part of the municipality of Stjørna (population: 676) were all merged to create a new, larger municipality called Bjugn. The population of Bjugn then increased from 1,240 to 4,940.
On 1 January 2018, the municipality switched from the old Sør-Trøndelag county to the new Trøndelag county.
On 1 January 2020, the neighboring municipalities of Bjugn and Ørland merged to become a single municipality called Ørland with its administrative centre at Botngård.